Amazon Prime Streaming Issues 7017

Sorry to bother the community.
I changed last weekend my old Desktop-PC for a Notebook. Since then, I am not able any more to stream films on Amazon prime now.
Some told me it were because of the Widevine Plug-in but it seems to be activated.
Any ideas? In the meantime, I stream through another browser, but I really like to stay for everything with Vivaldi.
Thank you in advance for all help.
Michèle

Pitching in: at first Amazon Prime wouldn't even recognize that I'm a subscriber. Now it gives me an error when attempting to play videos, and tells me to see www.amazon.com/dv/error/7031, "Resolve Issues with the Chrome Web Player."